1. Field of the Invention
This invention relates to electrical distribution systems used primarily in buildings and specifically to telephone and data communications distribution systems.
2. Description of the Prior Art
Electrical systems, such as telecommunications distribution systems used in large buildings, must provide some means to properly distribute incoming circuits to the proper location within a building. A practical premise distribution system must have both the capability of distributing large number of circuits and the capability of being reconfigured as circumstances may subsequently require. For example, a telephone distribution system must permit easy relocation and redistribution of telecommunications equipment and circuit assignments.
For large office buildings, a central distribution assembly is generally provided. In conventional telecommunication systems, multiconductor cables normally comprise the incoming circuitry at the building entrance location and 25 pair cables or larger serve as riser cables normally extending between the building entrance, or primary closet, and other distributed locations or satellite closets. Cross connect capability is necessary in both the primary closet and the satellite closets. For telecommunications equipment, this cross connect capability means that one or more pairs in the outgoing cable or conductors must be selectively connected to a corresponding number of pairs in the incoming cables. Since the cross connect capability is intended to permit selectablity between incoming and outgoing pairs, the cross connect means must be suitable for providing interconnection for any single pair or group of pairs in the outgoing cable to any single pair or group of pairs in the incoming cable.
A conventional apparatus for achieving such cross connect capability would include a wiring block assembly and a connecting block assembly. Generally, conductors in a plurality of incoming or outgoing cables would be deployed and attached or terminated in a plurality of rows on a wiring block apparatus mounted in either the primary closet or the satellite closet. A separate wiring block would be provided for the incoming cable, and another wiring block would be provided for the outgoing cable. Cross connect capability would be provided by use of jumper assemblies consisting of connector blocks attached at opposite ends of one or a group of jumper wire pairs. One jumper cable connector could be connected to prescribed adjacent pairs on the incoming wiring block and a second connector block attached to the other end of the jumper wire would be similarly connected at the desired location in the outgoing wiring block. Conversely, simple jumper wires, which could be terminated to insulation displacement type terminals in the incoming and outgoing wiring blocks could be employed by the jumper.
One example of this latter type of cross connect assembly is the 66 connecting block system manufactured by AT&T. These 66 type blocks employ quick clip or insulation displacement terminals for interconnection to a wire. These 66 type blocks are generally mounted on a bracket which defines a trough between the face of the bracket and the wall or panel on which the bracket is mounted. Cables are routed in the trough and around on the exterior to deploy the individual wires for termination into the clip type contacts in the 66 block. Resilient latches extend from the sides of these mounting brackets to engage the base of conventional 66 type mounting blocks. One bracket of this type is referred to an 89 type mounting bracket and is manufactured by Western Electric. Since these 66 type blocks and 89 type brackets have been in wide use for a number of years, a number of installations employ these conventional 89 type brackets for wire management purposes. However, the 66 blocks do have certain disadvantages in terms of facilitating quick and easy repositioning of the jumpers.
Although many cross connect systems do employ cross connect blocks in which the wires in a multiconductor cable are attached directly to the wiring block or cross connect block, some conventional cross connect systems employ connectorized cable systems in which miniature ribbon connectors are used to interconnect the cross connect apparatus to connectorized cables. Miniature ribbon connectors consist of connectors having a plurality of terminals side by side in two rows. Since these connectors are generally used with cables having a plurality of associated wire pairs, terminals in corresponding positions within the same row would be attached to the wires corresponding a particular pair. Male and female connectors could then be intermated to join the miniature ribbon connector attached to a cable to a separate miniature ribbon connector, in turn attached to cross connect terminals by wires or other means. In some assemblies, the conventional wiring blocks are factory assembled with wires leading from corresponding positions on the wiring block to the appropriate position on the associated miniature ribbon connector.
U.S. Pat. No. 4,662,701, discloses a cross connect system which employs miniature ribbon connectors without the need of separate cross connect terminal assemblies. This patent application discloses a single pair interconnect system in which the jumper plugs mount directly with the terminals on a female miniature ribbon connector. That invention, however, only provides interconnection between two identical ribbon connectors. A true cross connect system would require interconnection not only between miniature ribbon connectors but also interconnection to work stations and telecommunications equipment which may employ cables which normally cannot be terminated by a miniature ribbon connector. The preferred embodiment of the invention disclosed herein provides a means for utilizing this single pair cross connect capability not only with connectorized cable but also with discrete wires, cables having a smaller number of conductors, and with connectors such as modular telephone jacks. Furthermore, the preferred embodiment of this invention provides a system which can be used in much the same manner as conventional cross connect systems but which will reduce the number of components employed in the cross connect system and will reduce the amount of labor necessary to install and maintain such systems. Furthermore, the preferred embodiment of this invention is specifically adapted for use with wire management hardware such as 89 type mounting brackets which are already in place in a number of buildings. Therefore, the preferred embodiment of this invention is suitable not only for new installations but for replacement of and updating existing cross connect systems which have neither the flexibility or capacity of the apparatus disclosed and claimed herein.